1. Technical Field
The present invention relates to a film touch sensor and, more particularly, to a film touch sensor that may meet requirements for both a transmittance and a color value (b*).
2. Description of the Related Art
As a touch input method is receiving attention as a next-generation input technique, many attempts are being made to apply such a touch input method to various kinds of electronics. Hence, thorough research and development is ongoing into touch sensors that are able to function under a variety of conditions and that also enable accurate touch recognition.
For example, in the case of electronics having touch-type displays, ultrathin flexible displays, which are lightweight and have low power consumption and improved portability, are receiving attention as next-generation displays, and thus, the development of touch sensors suitable for use in such displays is required. Briefly, there is the demand for a touch sensor having high bendability, restoring force, flexibility, and stretchability.
A film touch sensor for manufacturing a flexible display is exemplified by a wire board configured such that a line is embedded in a transparent resin base. Such a board is manufactured through a line formation process for forming a metal line on a substrate, a stacking process for applying and drying a transparent resin solution to form a transparent resin base so as to cover the metal line, and a stripping process for stripping the transparent resin base from the substrate.
In order to efficiently perform the stripping process in the aforementioned manufacturing method, an organic stripping material, such as a silicone resin or fluorine resin, or an inorganic stripping material, such as a diamond-like carbon (DLC) thin-film or a zirconium oxide thin-film, may be formed in advance on the surface of the substrate.
However, in the case where the inorganic stripping material is used, when the base and the metal line are stripped from the substrate, the line and the base are not efficiently stripped, and a portion thereof may thus be left behind on the surface of the substrate. Also, the organic material used as the stripping material may become stuck to the surface of the base and the line.
With the goal of solving such problems, Korean Patent No. 10-1191865 discloses a method of manufacturing a flexible substrate, including forming a sacrificial layer able to be removed using light or a solvent, a metal line and a polymer material (a flexible substrate) on a substrate, and removing the sacrificial layer, thereby stripping the metal line and the polymer material (the flexible substrate) from the substrate. However, it is difficult to remove the sacrificial layer on a large scale, and high-temperature processing cannot be performed, making it impossible to use various kinds of film bases.
As for the film touch sensor, which essentially includes the insulating layer, the transparent conductive layer and the passivation layer, it is difficult to meet requirements for both a transmittance and a color value (b*) when these layers are present. Hence, these problems are in need of being solved.